MEK fejléc (Bibliographic data, in Hungarian)

NICHOLAS KURTI, fellow of the Royal Society
Oxford University, U.K.

## SOME SZILARD REMINESCENCES

Berlin

I first met, or, to be more precise, saw Szilard in Berlin in 1929 when he was Einstein's assistant. He was a regular attender at the famous, almost fabulous, Wednesday Laue Colloquia, when people, from professors down to "Doctoranden" gave 20-30 minute reports on recently published physics papers. They addressed an audience of 80-100 which usually included seven Nobel Laureates, some already honored (Einstein, Planck, Nernst, Max von Laue, Gustav Hertz), some future (Schrödinger, Wigner).

Oxford

Szilard came to Oxford in 1935. The head of the Clarendon Laboratory, F.A. Lindeman (later Lord Cherwell) obtained for him an I.C.I. (Imperial Chemical Industries) grant similar to those which supported other emigré scientists from Central-Europe such as F. E. Simon, K. Mendelssohn, H. London, myself, etc. Lindeman did not want to copy the Cavendish Laboratory, which until the early 1930s, i.e. until the rise of Kapitza's Royal Society-Mond Laboratory, was almost entirely devoted to nuclear physics. Lindeman wanted the Clarendon to be "multidisciplinary". By the time Szilard arrived there was a flourishing low-temperature team under Simon, a small group on atomic spectroscopy (D. A. Jackson, H. G. Kuhn), high temperature thermodynamic properties (A. C. Egerton), and some work on infrared spectroscopy. He now wanted nuclear physics work to get going and Szilard, with his interest in neutrons seemed a good choice. I now quote from the recently published excellent book "Science at Oxford 1914-1939 - Transformation of an Arts University" by Jack Morell:

"For two years, from 1935 Szilard and his two collagues [both of them College tutors and post-doctoral research workers] worked on slow neutrons and their absorption but his character and concerns precluded him from achieving for nuclear physics what the group of Simon and Mendelssohn was doing in cryophysics. Szilard was restless, alternating intense work with absence from the laboratory. By summer 1937 he was so worried about the situation in Europe that he told Lindeman that in future he wished to spend at least half of his time in the U.S. and the rest in Oxford. Though Lindeman deplored this scheme it was formalized on 1 January 1938. By autumn 1938, after the Munich crisis, Szilard had resigned his I.C.I. Fellowship and lived thereafter in the U.S. A brilliant, mercurial and exotic bird of passage, Szilard's style was to live in Oxford from two 18-inch suitcases [NK's note: I believe that one of these contained his personal requirements, the other his counters and samples of a variety of materials for measuring neutron absorption] and not even to start the slogging work of inducting research pupils into the skills of making working apparatus. A quintessential maverick he was not the easiest man to have as a laboratory colleague: in 1938 the charitable Simon told him that he had exhausted the patience of his Oxford friends and of I.C.I. On one occasion Szilard wanted two dustbins full of paraffin wax for experiments on neutrons; in the event he ordered a ton of wax which duly filled the dustbins and many other containers long after his departure."

I remember another example of excessive supply of equipment for Szilard. In those days most people in the lab smoked and one time people were surprised at Szilard's generosity in offering them cigarettes, - "Take 2 or 3 or 4" - he would say. It was even more puzzling since, as far as I remember, he was not a smoker. He solved the mystery by explaining that Player's Navy Cut cigarettes came in light metal boxes and that these were ideal for holding his neutron absorption samples. It was suggested to him that he should order the tins direct from the manufacturers. So he wrote to Players in Bristol, telling them that he found their Navy Cut tins excellent for his neutron experiments, who were their suppliers? Players were so pleased with their boxes being used in scientific work that they immediately sent him five dozen empty tins.

Szilard was always interested in what was going on in the world and read newspapers avidly, and if something caught his eye he would follow it up. One day he turned up in the lab and mentioned very gravely that there were 3 cases of cholera in London. No one paid much attention. A couple of days later he said that the number of cases had increased to 20, but it was not until, a few days later, he mentioned several hundred cases and some deaths that people questioned him as to where he had got this news item. - "The Times." - "Show it!" - He did so. It was indeed there in a column headed "The Times, 100 years ago."

I sometimes wonder whether it was his preoccupation with the then recent discovery of the neutron that made Szilard quote Rutherford's "Energy from the atom, moonshine" out of context. What Rutherford really meant was that, contrary to the speculations of the popular press, to create cheap energy by bombarding materials with accelerated particles was moonshine.

I remember one amusing occasion when I completely misinterpreted Szilard's behaviour. I think it was in the summer of 1937 that he told me that Trude (Weiss, whom he later married) would like to have tea on the river Cherwell. Could he borrow my canoe for the afternoon. We arranged to meet in the orchard by the river bank where I kept the canoe. Szilard looked suspiciously at the fragile canoe, then sat in it and, rocking to and fro, found it comfortable. He then remarked that, with the canoe on the grass under an apple tree, the gently flowing water which he could almost reach from the canoe, all the conditions of a pleasant river outing were fulfilled, so why the additional fuss of putting the boat into water? Why not have tea in the canoe but on dry land? I admired his convincing argument; cold logic against unnecessary sentimental frille, but Trude would have none of it and they paddled away. - It was some thirty years later when, after Leo's death, Trude visited England that I reminded her of that incident and of my explanation. But I was wrong. Trude explained that Leo never learnt to swim and had an almost pathological fear of drowning.

La Jolla

In the spring of 1964 I visited La Jolla to give a seminar talk. When I discovered that Szilard lived in the same motel where I was booked in I rang him and we arranged to meet for breakfast. That was our first meeting since the Oxford days and he had hardly changed. We had a pleasant exchange of reminiscences and he told me that he had just sent off the manuscript of a paper on memory to the National Academy of Sciences for publication in Science. He was rather proud of his new theory. Although he knew it was wrong, as are all the other theories, it would be more difficult to demolish. He died a few weeks later. I wonder whether the paper was published.